Chemical analysis processes commonly practiced currently are roughly divided into four steps: (1) sampling, (2) pretreatment, (3) analysis and measurement, and (4) data processing. For example, environmental analysis of river water and wastewater from plant and biochemical analysis such as clinical test often demand analysis of a trace amount of substance, and thus demand a concentration step essentially for pretreatment. However, the operation demands a vast amount of labor and period. Recently developed was a new concentration method of making only an analyte substance in sample adsorbed on a special filler, washing the filler in a fluid, and extracting the analyte substance in sample at a higher concentration by extraction with an eluant. Although the method simplifies the concentration operation described above, the operation should be repeated if there are many kinds of analyte substances in the sample.
Analytical pretreatment is aimed at previously treating a sample or the analyte substance therein properly to make the trace analysis and measurement performed accurately and rapidly. The main purposes are prevention of change of desired substances over time, improvement in accuracy and sensitivity, removal of measurement-disturbing substances, protection or prevention of deterioration of the column and analytical instrument, simplification of analysis and measurement operation, and others. It is not possible to obtain accurate analytical results without proper pretreatment.
Unit operations in the analytical pretreatment include a) weighing, b) extraction, c) cleaning, d) filtration, e) dehydration/demineralization, f) concentration/dilution, g) derivatization, and h) addition of standard substance. These operations were mostly performed manually, and the chemistry devices and tools used were not common in the unit operations and each operation should be carried out by a different operator. The operational accuracy, which depends largely on the skill of the operator, varies significantly, and such an operation demanded a large amount of labor.
On the other hand in the fields of biochemical and environmental analysis, under progress is a research for miniaturization and automation of analytical instrument by using MEMS (micro-electro-mechanical system) technology. Single-function mechanical components (micromachines), components of analyzer, such as mircropump and micro valve have been studied (see, for example, Shoji, “Chemical Industry”, Kagaku Kogyo, November 2001, 52, 11, p. 42-46, and Maeda, “Journal of Japan Institute of Electronics Packaging”, Japan Institute of Electronics Packaging, January 2002, 5, 1, p. 25-26).
It is necessary to put together various multiple parts such as micromachines into a system for desirable chemical analysis. Generally, such a system thus integrated is called a micro total analysis system (μTAS). Normally, such a micromachine is formed on, for example, a silicon chip by application of semiconductor manufacturing process, or on a plastic material such as acrylic or silicone resin. It is in principle possible to integrate multiple components on one chip (integration) into a system, and such studies were also made (see, for example, korenaga, “50th National Congress for Environmental Studies, Science Council of Japan”, 1999, 14, p. 25-32). However, the production process is complicated, and it would be difficult to produce such a system at the mass production level. In contrast, International Publication WO 03/070623 discloses a method of using a hollow filament as channel as it is placed at a particular position. The method allows crosswise installation of channels and production of a device having a number of channels relatively easily.